Economists of the classical school were right to define a monopoly as a government-grant privilege, for gaining legal rights to be a preferred producer is the only way to maintain a monopoly in a market setting. Predatory pricing cannot be sustained over the long haul, and not even the attempt should be regretted since it is a great benefit to consumers. Attempted cartel-type behavior typically collapses, and where it does not, it serves a market function. The term "monopoly price" has no effective meaning in real market settings, which are not snapshots in time but processes of change. A market society needs no antitrust policy at all; indeed, the state is the very source of the remaining monopolies we see in education, law, courts, and other areas.
Amazon is just another big company that benefits from corporatocracy.